Optimization of prostate cancer diagnosis by increasing the number of core biopsies based on gland volume.

In this prospective, non-randomized phase-I clinical trial, we comparatively studied the performance of six laterally-directed biopsies or the modified fan-shaped biopsies (MFSB), midline sextant biopsies (MB), and transition zone biopsies (TZB) and examine their prostate cancer (PCa) detection rates. A total of 114 patients received combinations of MFSB, MB, and TZB based on prostate gland volume: those ≤15 cc received 8 biopsies; those >15 cc but ≤ 50 cc received 14 biopsies; and those >50 cc received 20 biopsies. The mean prostate-specific antigen (PSA) level, Gleason score, and prostate volume were 8.0 ng/ml, 6.4, and 47 cc, respectively. PCa detection rate of the MB was 25% while the MFSB was 22%. The overall PCa detection rate was 33.3% with all biopsies. PCa and high-grade prostatic intraepithelial neoplasia (HG-PIN) detection rates decrease as the size of the prostate increases. PCa detection rates were 50.0% for volumes ≤19.9 cc and volumes of >50 cc had a detection rate of 25.8%. PSA levels of <3.0 had PCa detection rates of 15% which increased to 58% with PSA levels >9.0. In a multivariate analysis, only TZB was significant for PCa diagnosed by PSA (β=7.4, p<0.01). Our study showed that it is important to perform both the lateral MFSB and the MB to improve overall PCa detections rates. Thus, we recommend performing MB, MFSB, and TZB based on prostate volume, as follows: 8 biopsies for ≤15 cc; 14 for those >15 cc but ≤50 cc, and 14-20 for those >50 cc.